I've looked around on the forums, but I still have questions about Metacam dosing. What's the max dose you guys have used for short-term use? I feel like the once a day dose wears off too quickly sometimes. In cases like that, is it best to just stick to that dose, or can the dose be split over 12 hours (if so, does that make it less effective)? Or can the pig even get a full dose twice daily?

TwoWhitePiggies, your vet may actually be wrong. Someone on the board (I forget who) contacted the publisher of Carpenter's Exotic Animal Formulary about a high meloxicam dose for rabbits (I think). It was a typo, 10 times the recommended dose. Will likely be corrected next edition.

My vet says they can get 0.5 mg/kg twice a day although that is way more than is recommended here. So I usuually give closer to the GL recommended amount. I am currently giving Hershey 0.15 cc twice day after her dental work on Wed. I will probably go to once a day tomorrow. She weighs around 900 grams.

We're double checking, but we raised a serious alarm when the KSU vet first sent us home with a large dose. She checked, and verified the dose, explaining that GPs have a very high metabolism, and that the dose per kilogram of body mass was higher for GPs and other small animals than it was for dogs.

Although I'm not sure what resources she checked, she is a vet at a Doctoral Research I level university with the only veterenary medicine program in the region.

Wrong, wrong, wrong. Your vet is using the rodent dosing guidelines for Metacam in the Formulary, which, according to an email that Mr. Carpenter himself sent me (after my former vet over-dosed the drug by 10x, and my discussions with the Formulary's publisher left us both puzzled about the major discrepancy), is based loosely on his expert's opinion of how rats metabolize the drug. While it's not a typo per se, your vet should notice that guinea pigs are specifically not listed under that drug in the rodent section.

The dosage for guinea pig needs to be based on the recommendation in the rabbit section of the book, which is .1-.2mg/kg.

EDIT TO ADD: This information was also backed up by Boehringer Ingelheim, the drug's manufacturer.

He didn't have any trouble with it and it helped him. I wouldn't go anywhere near that high for very long, though.

For more 'regular' use, even on a short-term basis, we've had success giving a little more than one-half the standard dose twice a day, rather than the full standard dose once a day. I think the highest we've used other than the exception above was 0.2 cc's, or 0.3 mg/kg for a one-kilo pig, twice a day. That was for a day or two only in each case.

Here's the e-mail that came back from our vet, Dr. Swenson, at K-State:

Diana,
Yes, this frequently confuses people (and vets) who look through Carpenter's formulary (this is the primary drug reference used for exotics, and happens to be edited by none other than our Dr. Carpenter, the head of the zoo service here at K-state). I asked Carpenter about this when I first noticed the discrepancy. In every other species of animal besides rodents, Metacam is listed at 0.1-0.2 mg/kg (since metacam is 1.5 mg/ml, this works out to be 0.06 ml to 0.13 ml for a 1 kg pig). However, in rodents, it has been tested at a dose range of 1 - 2 mg/kg. IN RODENTS ONLY! This is what is listed in Carpenter's formulary. It is NOT a typo and it will not be changed in future publications as it has solid evidence behind it to support it. It is confusing since all other species are listed at 0.1-0.2 mg/kg. This is mostly because the studies at these high doses haven't been done yet in species other than rodents.

So, don't worry, this is not a massive overdose. In a rabbit, it could be, but guinea pigs tolerate metacam very well. Now one thing that I should clarify in what you said was that GPs can get up to 2 mg per kg of body weight, not 2 ml per kg. At the 1.5 mg/ml concentration, this means that for a 1 kg GP (like Gilbert) the dose range is from 0.7 - 1.4 mls of metacam in a 24 hour period (hence why Gilbert is up at 1.3 ml).

Feel free to add this to the list. Every situation is unique, and when
starting pigs on metacam, we typically start at a dose of 0.3-0.4 mg/kg just to be safe. However, I have quite a few rodents now on much higher doses, such as what Gilbert is on with no side effects. Rodents seem to tolerate the drug quite well and don't have the same sensitivity to the GI side effect that other species do. Having said that, I don't recommend anyone playing around with the doses of any drugs without consulting their veterinarian, but I think it's important to clarify that the listing in the formulary is NOT a typo.

I wonder if I kept my email from earlier this year. Dr. Carpenter had forwarded my question on to his source in the UK -- the person who had done experiments on lab rats and mice, and had made the determination that a dose of 1-2mg/kg was most effective for their faster metabolism. Carpenter's listing in the rodent section is based on this individual's personal recommendation, but Carpenter himself was a little vague as to whether or not he felt it should be applied to guinea pigs. If you look at the Formulary in the Rodent section, there is no listing for guinea pig under Metacam -- it says "rats/mice." With other drugs, it specifically states the dosage for guinea pigs where applicable.

Technically, no -- it's not a typo. But it's not very clear, either.

What was the most convincing for me, though, was my discussion with a rep from Boehringer. When I initially told this person that my vet had prescribed Metacam at 1-2mg/kg, the rep (I probably still have her name at work, if anybody wants to contact her directly) stated that this was "unusually high." She went on to say that their 'unofficial' recommendation for off-label use (since Metacam for guinea pigs is considered off-label) is roughly 1 drop per pound. She said that many vets don't bother to actually calculate this out for smaller animals, since it's such a small amount. Obviously, 2ml of Metacam is not a small amount. The rep also faxed me the information that they refer vets and other individuals to when they inquire about administering Metacam for guinea pigs. It's the rabbit section of Carpenter's Formulary -- not the rodent section. This is when I decided to buy the book and see for myself.

I'm no vet and I'm certainly no expert in this drug, but based on Carpenter's explanation, I tend to go with the manufacturer on this one and err on the side of caution.